package Wust_Java_Club_Middle_Test;

import java.util.Scanner;

public class Multiple {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int n = sc.nextInt();
		int ans = 0;
		for(int i=1;i<=n;i++) {
			ans+=n/i;
		}
		System.out.println(ans);
	}
}
